/* Tabs: Code and result
******************************/
function toggle_visibility(id) {
var e = document.getElementById(id);
if (e.style.display == 'none') {
for (var i = 0; i <
document.getElementsByName("khoiho").length; i++) document.getElementsByName("khoiho")
[i].style.display = 'none';
e.style.display = 'block';
} else e.style.display = 'none';
}